Put the instruction video on the thing it explains.
A channel, or one specific video. Print it on the product, the packaging or the wall beside the machine — the place where somebody is standing when they need it, holding the object and not a laptop.
More style options
Light grounds only — the code has to stay darker than what it sits on.
Where these earn their keep
Products and packaging
Assembly, setup, what the third button does. A sixty second video answers what a folded sheet of diagrams does not, and costs nothing to print on the box.
Machines, equipment and signage
In the workshop, the gym, the laundry room. The person who needs the instructions is never the person who read the manual.
Exhibitions and venues
A label beside the thing, pointing at the curator explaining it. Deep enough for anyone who wants it, invisible to anyone who does not.
Questions people ask
Can I link to one video rather than my channel?
Yes. Paste the video link and it goes through as given, including a start time if you copied one. Type a bare handle instead and you get the channel.
Does it open in the YouTube app?
If they have it installed, yes — the phone recognises the address and hands it over. Otherwise it opens in the browser and plays there.
Is this the same as YouTube's own QR code?
No. Theirs lives in the app under Share, which is fine phone to phone and no use printed on a box — the person has to already be in YouTube. This is an ordinary code any camera reads.